The present invention relates to new and useful improvements in furnaces for burning solid fuel and has particular reference to furnaces especially adapted for the burning of wood or coal as a fuel.
Wood burning stoves or furnaces have in recent years enjoyed a resurgence of popularity in direct proportion to increasing cost of normal energy sources such as fuel oil, natural gas and electricity.
Conventionally such stoves included a fire box which is located with an opening to the fire box for refueling. Air is in general circulated around the fire box to provide heating for air to be supplied to a space to be heated.
In the prior art arrangements one disadvantage has been that a fire bed of wood or coal once ignited tends to continue to burn until it is consumed regardless of whether the zone being heated actually requires or needs heat at any given time.
The prior art has addressed this problem as shown in U.S. Pat. No. 423,653 where a bi-metallic temperature element is provided to operate a hinged door where the bi-metallic temperature element senses the temperature of the stove and controls air flow in response to firebox temperatures. While such an arrangement has provided some advantages over the art prior, the reference has inherent disadvantages which are overcome by arrangements provided by the present invention.
Other prior art references relate to regulation of combustion to a combustion chamber are shown in U.S. Pat. Nos. 4,074,854-Kamper; 1,834,958-Martin; 177,121-Hayes; 4,149,671-Cagle.
No prior art reference is known where a bi-metallic temperature control device is placed in the stream of air emitted from the furnace to the space to be heated and operates a combustion air flow device to regulate the flow of combustion air to the the combustion chamber in accordance therewith.